==========================================================================
Ubuntu Security Notice USN-6727-1
April 10, 2024

nss vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 23.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

Several security issues were fixed in NSS.

Software Description:
- nss: Network Security Service library

Details:

It was discovered that NSS incorrectly handled padding when checking PKCS#1
certificates. A remote attacker could possibly use this issue to perform
Bleichenbacher-like attacks and recover private data. This issue only
affected Ubuntu 20.04 LTS. (CVE-2023-4421)

It was discovered that NSS had a timing side-channel when performing RSA
decryption. A remote attacker could possibly use this issue to recover
private data. (CVE-2023-5388)

It was discovered that NSS had a timing side-channel when using certain
NIST curves. A remote attacker could possibly use this issue to recover
private data. (CVE-2023-6135)

The NSS package contained outdated CA certificates. This update refreshes
the NSS package to version 3.98 which includes the latest CA certificate
bundle and other security improvements.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 23.10:
   libnss3                         2:3.98-0ubuntu0.23.10.1

Ubuntu 22.04 LTS:
   libnss3                         2:3.98-0ubuntu0.22.04.1

Ubuntu 20.04 LTS:
   libnss3                         2:3.98-0ubuntu0.20.04.1

This update uses a new upstream release, which includes additional bug
fixes. In general, a standard system update will make all the necessary
changes.

References:
   https://ubuntu.com/security/notices/USN-6727-1
   CVE-2023-4421, CVE-2023-5388, CVE-2023-6135

Package Information:
   https://launchpad.net/ubuntu/+source/nss/2:3.98-0ubuntu0.23.10.1
   https://launchpad.net/ubuntu/+source/nss/2:3.98-0ubuntu0.22.04.1
   https://launchpad.net/ubuntu/+source/nss/2:3.98-0ubuntu0.20.04.1